1. Field of the Invention
The present invention is in the field of optics and relates particularly to small anamorphic lenses useful for special applications such as beam shaping, optical scanning, and optical coupling among small light guides, light sources, and light detectors.
2. Description of the Prior Art
Imaging optical systems wherein the magnification of an image at the image plane differs in two perpendicular directions, typically horizontal and vertical, have been referred to as anamorphic optical systems. One such system, described by I. Powell, Applied Optics, 22, (20), pages 3249-3257 (1983), includes prismatic components to expand or compress the field of light traversing the system in one direction. Wide-angle single-component anamorphic lenses have been described by Y. Goncharenko et al., Sov. J. Opt. Technol., 37 (11) pages 725-728 (Nov. 1970), and the design of lenses for shaping laser radiation has been discussed by A. Tsibulya et al., J. Sov. Opt. Technol., 44, (3) pages 140-142 (March 1977).
In addition to utility in photographic and photographic enlargement systems, multicomponent anamorphic lenses have been used in other photographic applications, such as in the reformating of motion picture images for television, as described in U.S. Pat. No. 4,288,818. Applications for single-element anamorphic lenses have included beam shaping for facsimile scanners, as disclosed in U.S. Pat. No. 3,886,309, and beam expanding for scanning optical measurement systems, as disclosed in U.S. Pat. No. 4,074,938.
Anamorphic lenses can be generated by grinding and polishing techniques or by thermoplastic molding processes. The latter, while seemingly more suitable to economical production, do not generally provide surfaces of optical quality, particularly when the molded material is molten glass. Thus a more economical technique for producing non-spherical glass lens material would be desirable.
It is one object of the present invention to provide a novel method for providing small glass anamorphic lenses wherein grinding and polishing of the lenses is not required.
It is a further object of the invention to provide small anamorphic lenses particularly suitable for use with small light emitters and detectors, e.g. semiconductor lasers.
Other objects and advantages of the inventions will become apparent from the following description.